<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>checkerboard-pattern</title>
    <style>
        .checkerboard {
            width: 240px;
            height: 240px;
            background-color: #fff;
            background-image: linear-gradient(45deg,
                    #000 25%,
                    transparent 25%,
                    transparent 75%,
                    #000 75%,
                    #000),
                linear-gradient(-45deg,
                    #000 25%,
                    transparent 25%,
                    transparent 75%,
                    #000 75%,
                    #000);
            background-size: 60px 60px;
            background-repeat: repeat;
        }
    </style>
</head>

<body>
    <div class="checkerboard"></div>
</body>

</html>